1. Field of the Invention
The present invention generally relates to a method and a system for power load management and, more particularly, to a method and a system for power load management capable of controlling the timing for unloading or reloading an electrical device according to power consumption thereof.
2. Description of the Prior Art
Due to the raise in oil and coal prices in recent years, the cost of generating power has significantly increased. Moreover, the green house effect worsens the global warming that ecologically affects the earth. Therefore, various measures for energy conservation have been taken throughout the world.
The air conditioner plays an important role in the summer for people living in the subtropical countries. Such an electric device is a power eater even though it brings forth comfort in the room during the summer. Statistically, the power consumption of the air conditioning systems occupies 30˜40% of the peak load in the summer. Therefore, it has been an important issue to provide comfort in the living/working places with reduced power consumption.
In the prior art, such as Taiwan Pat. Pub. No. 200742819, there is disclosed a power saving device disposed in and electrically coupled to a temperature adjustment device. The power saving device comprises at least a temperature sensor, a processing unit and a switching unit. The temperature sensor issues a sensed signal of temperature to the processing unit, which generates a switching signal according to sensed signal. The switching unit switches a compressor to an operation state or a static state according to switching signal.
Moreover, Taiwan Pat. No. 175182 discloses a power control device for a centralized air conditioning system, using the outdoor temperature, the indoor temperature, the temperature of water flowing from/into the cooling tower and the pre-set temperature as control parameters to control the compressor, the cooling pump and the fan in the cooling tower of the air conditioning system according to a software program to provide comfort with reduced power consumption.
Moreover, U.S. Pat. No. 6,493,643 discloses a power control method capable of controlling the operation of electrical devices within a zone according to the detected total power consumption. This patent is useful in power saving management for home-use electrical devices. More particularly, the method uses a controller acquires real-time power consumption information of the electrical devices from the AC utility via internal communication devices to compare with a maximum value determined by a logical controller, time-of-use electricity tariff and the operation state of the electrical devices to generate a signal to the home-use plugs to control the power consumption. In this patent, the power consumption is compared with a standard value, which causes shed-load or reload of the system due to poor control accuracy.